TITLE: GCN GRB OBSERVATION REPORT NUMBER: 48 SUBJECT: GRB980329 optical observations DATE: 98/04/06 19:07:37 GMT FROM: Elena Pian at TESRE-CNR,Bologna E. Palazzi, N. Masetti, E. Pian, F. Frontera (ITeSRE-CNR, Bologna), L. Nicastro (IFCAI-CNR, Palermo), P. Vreeswijk, T. Galama, P. Groot, J. van Paradijs (U. Amsterdam), M. Della Valle (Oss. Astr. Padova), E. Costa, M. Feroci, L. Piro (IAS-CNR, Rome), C. Kouveliotou (MSFC-NASA), and C. Lidman (ESO) report: The error box of GRB980329 (IAUC 6853) was observed with the NTT at ESO (La Silla, Chile) on March 29.99, 30.99 and April 1.01 UT with EMMI in R and V band filters. Observations lasted 10+10 minutes per filter per night. Limiting magnitudes were ~24.0 in R and 23 in V. On March 29.99, at the position RA = 07h02m38s, Dec = +38deg50'44".1 (J2000), coincident (to within the astrometric errors) with VLA J0702+3850 (GCN #40) and with the galaxy reported by Djorgovski et al. (GCN #41), we detect an R = 23.5 (+/- 0.2) object. The source is not detected in V, and in the subsequent nights is undetected in both bands. Using R = 25.7 (April 2, Djorgovski et al., GCN #41) we obtain a luminosity power-law decay index <~ -1.3. The extrapolation of this power-law to the time of the observations reported by Guarnieri et al. (GCN #37, Mar 29.79), Brocato et al. and Cappellaro (see below) is consistent with their non-detections. The NTT R band images can be found at the Web site http://www.tesre.bo.cnr.it/~nicastro/grb980329, as well as the TIRGO J band images reported in GCN #46. In addition: E. Brocato, A. Piersimoni, and G. Raimondo (Oss. Astr. Teramo) report: We imaged the GRB980329 error circle with the 0.72-m telescope at Campo Imperatore (Teramo) equipped with a Tek-CCD and R band filter on March 29.83 UT for 1800 s. No object brighter than R = 20 is detected at the VLA source position. E. Cappellaro (Oss. Astr. Padova) reports: On March 29.81 and 29.99 UT, the GRB980329 error circle was imaged for 1500 s using the 1.8-m telescope at the Asiago observatory with AFOSC and R band filter. Down to a limiting magnitude of R = 21, no object is found at the VLA source position.